Impact of Perioperative Phosphorus and Glucose Levels on Liver Regeneration and Long-term Outcomes after Major Liver Resection

The Association Between Low Preoperative Phosphate Levels and Postliver Surgery Outcomes-A Single Center Experience

INTRODUCTION

Previous research has demonstrated the impact of postoperative phosphate levels on liver regeneration and outcomes after liver resection surgeries, a potential predictor for regenerative success and liver failure. However, little is known about the association between low preoperative serum phosphate levels and outcomes in liver resections.

METHODS

We performed a retrospective analysis of liver resections performed at our institution. Patients were categorized based on preoperative phosphate levels (low versus normal). Our primary outcome measure was posthepatectomy liver failure.

RESULTS

A total of 265 cases met the study criteria. 71 patients (26.7%) had low preoperative phosphate levels. The incidence of posthepatectomy liver failure was higher in the low preoperative phosphate group (19.2% versus 12.4%). However, after propensity score matching, rates of posthepatectomy liver failure were similar between low and normal preoperative phosphate cohorts (13% versus 14%, P = 0.83).

CONCLUSIONS

Low preoperative phosphate levels were not associated with worse postoperative outcomes in this study. Further studies are warranted to investigate this association and its relevance as a clinical prognostic factor for postoperative liver failure.

Early Postoperative Serum Phosphate Drop Predicts Sufficient Hypertrophy After Liver Surgery

OBJECTIVE

The aim of this study was to assess the impact of postoperative hypophosphatemia on liver regeneration after major liver surgery in the scenario of Associating Liver Partition with Portal vein ligation for Staged hepatectomy (ALPPS) and living liver donation (LLD).

BACKGROUND

Hypophosphatemia has been described to reflect the metabolic demands of regenerating hepatocytes. Both ALPPS and LLD are characterized by an exceptionally strong liver regeneration and may be of particular interest in the context of posthepatectomy hypophosphatemia.

METHODS

Serum phosphate changes within the first 7 postoperative days after ALPPS (n=61) and LLD (n=54) were prospectively assessed and correlated with standardized volumetry after 1 week. In a translational approach, postoperative phosphate changes were investigated in mice and in vitro .

RESULTS

After ALPPS stage 1 and LLD, serum phosphate levels significantly dropped from a preoperative median of 1.08 mmol/L [interquartile range (IQR) 0.92-1.23] and 1.07 mmol/L (IQR 0.91-1.21) to a postoperative median nadir of 0.68 and 0.52 mmol/L, respectively. A pronounced phosphate drop correlated well with increased liver hypertrophy ( P <0.001). Patients with a low drop of phosphate showed a higher incidence of posthepatectomy liver failure after ALPPS (7% vs 31%, P =0.041). Like in humans, phosphate drop correlated significantly with degree of hypertrophy in murine ALPPS and hepatectomy models ( P <0.001). Blocking phosphate transporter (Slc20a1) inhibited cellular phosphate uptake and hepatocyte proliferation in vitro.

CONCLUSION

Phosphate drop after hepatectomy is a direct surrogate marker for liver hypertrophy. Perioperative implementation of serum phosphate analysis has the potential to detect patients with insufficient regenerative capacity at an early stage.

Impact of liver volumetric regeneration on survival outcomes in patients with hepatocellular carcinoma after major hepatectomy

PURPOSE

Prognostic value of liver volumetric regeneration (LVR) in patients with hepatocellular carcinoma (HCC) who undergo major hepatectomy remains unknown. The aim of this study was to investigate the impact of LVR on long-term outcomes in these patients.

METHODS

Data of 399 consecutive patients with HCC who underwent major hepatectomy between 2000 to 2018 were retrieved from a prospectively maintained institutional database. The LVR-index was defined as the relative increase in liver volume from 7 days to 3 months (RLV3m/RLV7d, where RLV3m and RLV7d is the remnant liver volume around 3 months and postoperative 7 days after surgery). The optimal cut-off value was determined using the median value of LVR-index.

RESULTS

A total of 131 patients were eligible in this study. The optimal cut off value of LVR-index was 1.194. The 1-, 3-, 5- and 10-year overall survival (OS) rate of patients in the high LVR-index group were significantly better compared to those in the low LVR-index group (95.5%, 84.8%, 75.4% and 49.1% vs. 95.4%, 70.2%, 56.4%, and 19.9%, p = 0.002). Meanwhile, there was no significant difference with regards to time to recurrence between the two groups (p = 0.607). Significance of LVR-index for OS was retained after adjusting for known prognostic factors (p = 0.002).

CONCLUSION

In patients with HCC undergoing major hepatectomy, LVR-index may serve as a prognostic indicator for OS.

Hypophosphatemia as a prognostic tool for post-hepatectomy liver failure: A systematic review

BACKGROUND

Post-hepatectomy liver failure (PHLF) is one of the main causes of postoperative mortality and is challenging to predict early in patients after liver resection. Some studies suggest that the postoperative serum phosphorus might predict outcomes in these patients.

AIM

To perform a systematic literature review on hypophosphatemia and evaluate it as a prognostic factor for PHLF and overall morbidity.

METHODS

This systematic review was performed according to preferred reporting items for systematic reviews and meta-analyses statement. A study protocol for the review was registered in the International Prospective Register of Systematic Reviews database. PubMed, Cochrane and Lippincott Williams & Wilkins databases were systematically searched up to March 31, 2022 for studies analyzing postoperative hypophosphatemia as a prognostic factor for PHLF, overall postoperative morbidity and liver regeneration. The quality assessment of the included cohort studies was performed according to the Newcastle-Ottawa Scale.

RESULTS

After final assessment, nine studies (eight retrospective and one prospective cohort study) with 1677 patients were included in the systematic review. All selected studies scored ≥ 6 points according to the Newcastle-Ottawa Scale. Cutoff values of hypophosphatemia varied from < 1 mg/dL to ≤ 2.5 mg/dL in selected studies with ≤ 2.5 mg/dL being the most used defining value. Five studies analyzed PHLF, while the remaining four analyzed overall complications as a main outcome associated with hypophosphatemia. Only two of the selected studies analyzed postoperative liver regeneration, with reported better postoperative liver regeneration in cases of postoperative hypophosphatemia. In three studies hypophosphatemia was associated with better postoperative outcomes, while six studies revealed hypophosphatemia as a predictive factor for worse patient outcomes.

CONCLUSION

Changes of the postoperative serum phosphorus level might be useful for predicting outcomes after liver resection. However, routine measurement of perioperative serum phosphorus levels remains questionable and should be evaluated individually.

Diabetes mellitus and postoperative blood glucose value help predict posthepatectomy liver failure in patients with hepatocellular carcinoma

Background

Many complications after hepatectomy can lead to perioperative death, among which posthepatectomy liver failure (PHLF) is the leading one. Existing studies suggest that one of the most important risk factors for PHLF is cirrhosis. Hepatitis B virus (HBV) infection is an important factor in the occurrence of cirrhosis, and the exact relationship between HBV infection and PHLF is not obvious. Diabetes mellitus and postoperative blood glucose are closely associated with liver regeneration, but its exact relationship with PHLF remains unclear.

Methods

We collected clinical indicators from 920 adult patients treated at the Liver Surgery and Transplantation Center of West China Hospital of Sichuan University from April 2009 and April 2019. We conducted a univariate analysis find out the risk factors of PHLF, follow by a multivariate analysis to ascertain the independent risk factors. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive efficiency of each risk factor.

Results

Following hepatectomy, 205 (22.2%) of patients were diagnosed with PHLF. Several variables were confirmed to related with PHLF significantly: diabetes [P<0.01, odds ratio (OR) =10.845, 95% confidence interval (CI): 5.450-21.579], HBV (P<0.01, OR =0.345, 95% CI: 0.187-0.635), blood glucose on the first postoperative day (post-BG1) (P=0.027, OR =1.059, 95% CI: 1.006-1.115), blood glucose on the third postoperative day (post-BG3) (P=0.021, OR =1.085, 95% CI: 1.012-1.162), blood glucose on the fifth postoperative day (post-BG5) (P=0.014, OR =1.119, 95% CI: 1.023-1.225), postoperative total bilirubin (post-TB) (P<0.01, OR =1.160, 95% CI: 1.133-1.187), and liver cirrhosis (P<0.01, OR =0.982, 95% CI: 0.561-1.717) identified to be independent risk factors of PHLF.

Conclusions

Diabetes, HBV, post-BG1, post-BG3, and post-BG5 are related to the development of PHLF, and diabetes and post-BG can be used as predictors of the development of PHLF in patients with hepatocellular carcinoma (HCC).

Liver-specific Sirtuin6 ablation impairs liver regeneration after 2/3 partial hepatectomy

Sirtuin 6 (Sirt6) is an NAD+-dependent deacetylase that regulates central metabolic functions such as glucose homeostasis, fat metabolism, and cell apoptosis. However, the tissue-specific function of Sirt6 in liver regeneration remains unknown. Here, we show that liver-specific Sirt6 knockout (Sirt6LKO) impaired liver reconstitution after 2/3 partial hepatectomy, which was attributed to an alteration of cell cycle progression. Sirt6 LKO delayed hepatocyte transition into S phase during liver regeneration, as shown by the analysis of cell cycle-related proteins and the immuno staining of Ki-67 and 5-bromo-2-deoxyuridine (BrdU). The delayed cell cycle in Sirt6 LKO mice was attributed to the disruption of m-TOR and Akt activity, which is an important pro-proliferation pathway in liver regeneration. Sirt6 LKO also reduced carbon tetrachloride (CCl₄ )-induced liver damage. Our results suggest that Sirt6 LKO impaired liver regeneration via delayed cell cycle and impaired m-TOR and Akt activity.

Hypophosphatemia after Hepatectomy or Pancreatectomy: Role of the Nicotinamide Phosphoribosyltransferase

BACKGROUND

Postoperative hypophosphatemia is common and is associated with a lower risk of liver failure after hepatectomy, but higher morbidity after pancreatectomy. Whether different physiologic mechanisms underlie the hypophosphatemia associated with these very different clinical outcomes is unclear. This study aims to evaluate the underlying mechanism in postoperative hypophosphatemia.

STUDY DESIGN

We prospectively enrolled 120 patients who underwent major hepatectomy (n = 30), minor hepatectomy (n = 30), pancreatectomy (n = 30), and laparotomy without resection (control group, n = 30). Preoperative and postoperative serum and urinary phosphorus, calcium, and creatinine, as well as phosphaturic factors, including serum nicotinamide phosphoribosyltransferase (NAMPT), fibroblast growth factor-23, and parathyroid hormone were measured. In addition, we evaluated urinary levels of nicotinamide catabolites, N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-3-carboxamide.

RESULTS

We found that significant hypophosphatemia occurred from postoperative day (POD) 1 to POD 2 in all 4 groups and was preceded by hyperphosphaturia from preoperative day to POD 1. Phosphate level alterations were associated with a significant increase in NAMPT levels from preoperative day to POD 2 in all 3 resected groups, but not in the control group. The fibroblast growth factor-23 levels were significantly decreased postoperatively in all 4 groups, and parathyroid hormone levels did not change in any of the 4 groups. Urine levels of N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-3-carboxamide decreased significantly in all 4 groups postoperatively.

CONCLUSIONS

This study demonstrates that the mechanism of hypophosphatemia is the same for both liver and pancreas resections. Postoperative hypophosphatemia is associated with increased NAMPT. The mechanism that upregulates NAMPT and its role on disparate clinical outcomes in postoperative patients warrant additional investigation.